Touch sensitive displays are becoming a popular interface on electronic devices for users to enter commands and data used in the operation of the device. Touch sensitive displays can now be found in mobile telephones, particularly portable music players, PDA (personal digital assistant) devices, and cellular telephones having integrated PDA features and other phone operation related features. The touch sensitive displays are generally designed to operate and respond to a finger touch, a stylus touch, or finger/stylus movement on the touch screen surface. Touch sensitive displays may be used in addition to, in combination with, or in place of physical keys traditionally used in a cellular phone to carry out the phone functions and features.
Touching a specific point on the display may activate a virtual button, feature, or function found or shown at that location on the display. Typical phone features which may be operated by touching the display include entering a telephone number, for example, by touching virtual keys of a virtual keyboard shown on the display, making a call or ending a call, bringing up, adding to or editing and navigating through an address book, and other phone functions such as text messaging, wireless connection to a wide area network, and other phone functions.
Commercial pressures to provide far more functionality within smaller physical device sizes are continuing to drive the need to provide more accurate determination of touch locations on a display.